Problem with Asterisk v1.4 recognizing Cepstral format

I am successfully generating a file with this command using Cepstral:

But then from Asterisk v1.4 I get the following:

[Feb 3 21:04:18] WARNING[1233]: format_wav_gsm.c:142 check_header: Unexpected header size 16 [Feb 3 21:04:18] WARNING[1233]: file.c:311 fn_wrapper: Unable to open format wav49 [Feb 3 21:04:18] WARNING[1233]: format_wav_gsm.c:142 check_header: Unexpected header size 16 [Feb 3 21:04:18] WARNING[1233]: file.c:311 fn_wrapper: Unable to open format wav49

I have had this working in previous versions. Ideas?